Interlocking means for the marginal edges of superimposed sheets



Jan. 8, 1 935. c, w. SADENWAT ER 1,937,217

INTERLOGKING MEANS FOR THE MARGINAL EDG'ES 0F SUPERIMPOSED SHEETS Filed July 30, 1954 16' M CHARLES TM. SADENWATER Patented Jan. 8, 1935 IN I ERLQGKI NG UBERIMZPOSEII' SHEETS? Charles W'- Sad'enwat'er,

to, Nationalwashboard Qompany; a-corporation-of West Virginia Y .Michy, 1 assignor Application July ;.1934; Serial-i Nos 7375484 4" Claims;

Thisinvention relates to-edge -binding or'lbcking means for-two sheets-ofmateriafthat isfoldable; bendable, or ductileasueh as" metal or the like', in flatw'i'se engagement; at least one of said sheets being corrugated? Such structures are usefulin various and sundry arts, and my invention in: its broadenaspects istb-b'esoconsidered: but for the purposeofpointihg out the'novel features of my improvement it will-b'e'll'eredescribed as it appears when applied totli'e rubbing surfaces of washboardshavingtwo'rubbing faces-mad'e of twomet'al sheets each-'corrugated so as't'opresent alternating ridges and channels, the two sheets beihg placed face to face so that points on thetbp' surfaces of their ridges are'contiguous, therid'ges of-"one'sh'eet being disposed criss cross arrangementwith respecttothe ri'dges -of 'theother sheet so that each rib'of one sheet serves as a transverse support for allof'theseveralribs-of tlie'othersheet.

Wash -boardsof sueli type are describedand claimed an application copending herewith; sesame: 7243-706, mews/rays; l934-by13harles'lfi Gilbert, and owned== by a common assignee of record? I I I In that application there is also shown and described a wash-board wherein the lateral edges of the two corrugated rubbing sheets are first flattened and then secured together so as to unite the two sheets into a unitary double-faced rubbing element, one face of which has horizontally disposed ribs and channels, the other vertical.

My present invention in the embodiment herein described pertains to a new and improved means for securing together the edges of two such corrugated rubbing sheets, although theedges of one sheet retain their original corrugated form, that is, they are not flattened.

The objects are, to impart to such a combined unitary rubbing face structure a greater degree of rigidity and strength, with less vibration of the sheets when in use and consequently less noise.

I attain the advantage of greater rigidity by a novel interlocking structure of the marginal edges of one of the two sheets, whereby the bottom portion of the trough of each corrugation of one sheet is individually fastened to the non-corrugated marginal edge of the other sheet in such a way as to hold all of the said corrugations in their proper spaced relation, and thereby prevent creeping when in use.

With the foregoing and certain other objects in view, which will appear later in the specifications, my invention comprises the devices described and claimed and the equivalents thereof.

Figs: Z- are diagrammatic face-views? of the two rubbihgelementsa: Fig. 3- is-'a-.fragmentary detailview sh'owing my improved means fonrastening together the eon tigu'o'us edgesof'sheets sucli as shown i-n' Fig'si .1 and- 2E Fig. 4 is a sectibnaldetail view ou line of Fig.3;

Fig. 5' is edge View of Y the parts shownin Fig; 4; as they appear-when seen in the directibrrot'the arrow, before the marginal edges of-tl ie two sheets are ihterlockedk Fig; 6 ie asectional view-partlybrokeniawayz showing a waslr-bozazrd embodying improve".-v ment ina-modified formtm -making arubbing elementacoordingi t'octhe illustrated embodiment of my inventi'om I pro?- vide two -corrugated'sheets 13', 2 of suoha relative size that when the sheets areil'aidi one .upom the other in the positions indicated bytherdottewlines inLFigs. 1: amaze. and inzrrigma theflat edges 1w, 1'a,'.ofisheet' 1 parallelawith thexribslb pros E's Pare NT a j jech-beyondathe:edgesrfimof itheothen sheet'Z, and

the edges- 2th,. 2a .ofi sheet 21Wi11 1 likewise; project beyond the edges 1c,1c of sheet 1. These projecting portions, for example the part 1a, indicated in Fig. 4 by dotted lines, are bent at right angles so as to present a flange 3 whose width'is preferably about equal to the height of the ribs 2b of sheet 2.

Portions 3a of the free edges of the flange 3 extend across the spaces between successive ribs 2b. They are bent inwardly and downwardly into the position indicated at 4, Figs. 3 and 4. Intermediate portions 3b of the flange are not bent. They form end wall abutments' for the ribs 2b. The part So when bent as described conforms with the shape of the wall of channel or 1 trough 2d and acts as a retaining ferrule or tang to lock each rib 21), against slipping, creeping or springing sidewise, endwise or up-and-down with respect to,the opposite sheet. The rigidity of both sheets 1, 2 is greatly increased by the above described interlocking arrangement and lighter and cheaper sheets can be used than would be permissible otherwise.

In some types of wash-boards it is advisable to provide on the assembled rubbing unit marginalv edges of appropriate'shap'e and thickness to be received as a close fit in grooves of standard width which are provided in the wash-board frame members 5, 6, in the manner shown in Fig. 6. In such cases a slightly modified form of flange 3 is used, there being an additional flange portion 7 on sheet 2 that laps over the faces of I 3 serves as a complete closure for the ends of the corrugations 1b beside preventing endwise movement of sheet 1, but they are not bent inwardly, as in the form shown in Fig. 3. Instead, flanges 3 and '7 enfoldthe end of corrugated sheet 1 and present. a..ten0n-.1ike edge to bereceived in the mortise-like groove off the wash-board frame.-

The edges'la of the flange portions 7 can be bent down so as to fit into the troughs between ribs. 2b, thereby locking the sheets against creeping} in the same manner as shown atin Figs. 3 and 4. Even the hardest rubbingtofwhich' a washboard is normally subjected in use does not. spring, stretch or distort the" co rru'gationsf. of the; two sheets when fastened together 'in'the manner above described. It prevents each sheet from rattling against the opposite 1 backing sheet." Moreover, the marginal edge of one sheet pro.-.-

vides an abutment wall for the end of the corrugations of the othersheet; greatly increasing. the

strength and rigidity oftheassembly.

The great ;degree of marginal rigidity of. the unitary structure characterized by my improvement renders it feasible;;to }use;,lighter sheets without impairing either the working strength i or thegstiffness of the completed rubbing element.

For purposes of description I have shownthe corrugated sheets with" smooth ridges and;v furrows in Figs. 1, 2, 3,5, and6, and with embossed ridges in- Fig. 4,;but my claimed invention is adapted to be used with any typeorform of ridged, ribbed, or fiutedsheets: having ridges; of any. suitable. or :usual. type, plain or embossed.

While I have shown and described both sheets as .being corrugated, ,itais obvious that 1 one of them maybe non-corrugated; Forexample, the corrugations, 1, Fig. 3,1 maybe omitted without departing from the invention asset forth in certain of .the'claims. i s

' Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1*. In a wash-boardrubbing element wherein two corrugated sheets of ductile material are superimposed in flatwise engagement with their 'respective ridges and furrows. lying in relatively criss-cross arrangement andin contact for mutual support, in combination, flanges on opposite edges of one of said sheets, parallel with the corrugations thereof, said flanges presenting abutments in engagement with the endsof' the corrugations on the other fsheet, spaced-apart portions of said flanges projecting into the ends of the furrows on said other sheet and engaging "the walls of said furrows, to secure the individual *corrugations, of each sheet against tendency to creep relatively to the other sheet under the conditions ofuse .of the rubbing element.

,1 2. I he invention asset forth in claim l'wherein the] spaced-apart portions of said flange are elongated and Wide and are shaped to fit closely the Walls of the said furrow over an appreciable area, in the manner of a ferrule.

3. In a wash-board rubbing element wherein two corrugated sheets of ductile material; are suo dw t th i res ect ri dr u rows lying relatively criss-cross arrangement and in contact for mutual support, in combination,;f anges on opposite edges of one. ofgsjaid sheets parallel with the corrugations thereof, said I flanges presenting; abutments in, engagement with the ends o-f the corrugations on the other sheet,

portions of said flanges enfolding thefends of" the corrugations on said other sheetv and,-engaging the same, edges of said flange portions being bent down into the furrows to grip the, other sheet and..to prevent movement of. one sheet relatively lother' .7. .1' v .1 4. A securing meansfor sheetsjofductilemetami or the like in flatwise-engagement, one having elongatedcorrugations spacedapart and present: ing furrows terminating atthe edgeofthe, sheet,

said securing meanscomprising tangs onthe-edge of the other sheet at the ends of the furrows, said tangs extending over uponand into, the respec tive furrowsw and lockingly engaging therewith in substantiallyferrule-like manner,

CHARLES W. SADENWATERQ 

